Straight-set retrievable packer



May 31, 1966 c. c. BROWN STRAIGHT-SET RETRIEVABLE PACKER 2 Sheets-Sheet1 Filed Aug.

CICERO CLBROW/V INVENTOR ATTORNEY y 1, 1966 c. c. BROWN 3,253,656

STRAIGHTSET RETRIEVABLE PACKER Filed Aug. 5, 1963 2 Sheets-Sheet 2 IC/CERO 6. BROWN y I NVENTOR.

NM BY A TERA/E) 3,253,656 STRAIGHT-SET RETRlEVABLE PACKER Cicero C.Brown, Brown Oil Tools, Inc., P.O. Box 19236, Houston, Tex.

Filed Aug, 5, 1963, Ser. No. 299,910 7 Claims. (Cl. 166129) Thisinvention relates to well packers and to improvements in packers of thestraight-set type.

Straight-set packers are understood in the art to mean packers which maybe set and released solely by longitudinal movement of the settingmandrel. Such straightset packers are employed where, due to theconditions of the well bore or other factors commonly encountered, it isundesirable to employ a type of packer which requires relative rotationbetween the setting string and the packer elements to actuate or releasethe packer.

It is a primary object of this invention to provide an improved form ofstraight-set packer which is universally useable for variouswell-treating processes, such as squeezing, fracturing, and the like, aswell as in well production operations.

A further object is the provision of a well packer of the straight-settype employing a novel arrangement of internal and external sealelements and latching elements by which the parts are releasably securedin inactive position, but are readily actuated in response tolongitudinal movements of the operating string.

An additional object is to provide a packer construction employing acentral mandrel on which are mounted a main packer unit, an anchorassembly, and an internal seal unit disposed for inter-engagement inresponse to longitudinal movements of the mandrel relative to the packerand anchor units.

A more specific object is the provision of a novel form of releasablelatch between the packer assembly and the mandrel for holding the packerassembly in inactive position during running of the packer into thewell.

Other and more specific objects and advantages of this invention willbecome more readily apparent from the following detailed descriptionwhen read in conjunction with the accompanying drawing which illustratesa useful embodiment in accordance with this invention.

In the drawing:

FIG. 1 is a longitudinal quarter-sectional view, showing the packer inthe unset position as it is run into a casing lining a well bore;

FIG. 2 is a view similar to FIG. 1, showing the packet elements at anintermediate stage during the setting operations;

FIG. 3 is a view similar to FIG. 1, showing the packer in set position;and

FIGS. 4, 5, 6 and 7 are cross-sectional views taken, respectively, alonglines 44, 5-5, 66 and 77 of FIG. 3.

The packer structure, which is insertable into a well casing W, includesa tubular mandrel M adapted to be connected into an operating pipestring T between upper and lower threaded collars C and C respectively,which forms downwardly and upwardly facing shoulders 10 and 11,respectively, at spaced points along the mandrel. A series ofsub-assemblies are slidably supported on mandrel M and comprise an upperlatch and inner seal assembly L mounted about the upper end of themandrel,

the main packer assembly S positioned about the mandrel below assemblyL, and an anchor assembly A disposed about the mandrel below packerassembly S. In their initial positions, the several assemblies aresupported in spaced apart relation on mandrel M by means of releasablelatch elements, to be described more fully hereinafter, but are arrangedto be inter-engaged in response to rela- United States Patent 0 PatentedMay 31, 1966 tive vertical movements of the mandrel, as will appearhereinafter.

Latch and inner-seal assembly L, which is of the same general form andarrangement disclosed in my co-pending application Serial No. 756,552,filed August 28, 1958, now Patent No. 3,136,366, includes a seal packing12 molded to upper and lower end rings 13 and 14, respectively, thepacking unit being disposed for limited sliding movement on mandrel Mbetween longitudinally spaced upper and lower snap rings formingexternal shoulders 15 and 16, respectively, about mandrel M. Slidablymounted about the latter above the seal packing is a latch sleeve 17slotted longitudinally from its lower end to form a series ofcircumferentially arranged flexible latch fingers 18 terminating attheir lower ends in outwardly projecting latching dogs 19. The latterhave bevelled inner faces 20 adapted to engage an upwardly taperingconical expander surface 21 formed on upper end ring 13. 'A third snapring 15a is mounted in the exterior of mandrel M to form an externalshoulder a short distance above shoulder 15 and is adapted to be engagedby an internal shoulder 17a provided at the upper end of latch sleeve 17to limit downward movement of the latter on mandrel M. Relative upwardmovement of sleeve 17 on mandrel M is limited by shoulder 10 defined byupper collar C.

Main packer assembly S includes a tubular packer body 22 having acounterbore 23 at its upper end adapted to sealingly receive sealpacking 12 and latching dogs 19. Counterbore 23 is provided internally,near its upper end, with a latching groove 24 for latching engagement bydogs 19 when the latch assembly has been inserted in body 22, as willappear subsequently. An annular, flexible, resilient packer or sealelement 25 is positioned about an intermediate portion of body 22 and issecured to upper and lower metal end rings 26 and 27, respectively.Upper end ring 26 is fixedly secured to body 22, while lower end ring 27and seal element 25 are free to slide on body 22, seal elements 25 beingradially expansible in response to end-wise compression exerted upwardlythrough lower end ring 27 against the fixedly positioned abutment formedby upper end ring 26. An external upwardly facing shoulder 24 providednear the lower end of body 22, co-operates with a downwardly facing internal shoulder 28 on end ring 27 to limit downward movement of the sealelement on body 22. A plurality of generally conventional wickeredhold-down buttons 29 will be mounted for radial movement in the wall ofbody 22 above the seal element and are adapted to be urged outwardly inresponse to hydraulic pressure interiorly of body 22 for engaging thewall of well casing W.

Lower end ring 27 has attached thereto surrounding body 22 a tubularslip cone B0 haw'ng a bore wall 30a and provided at its lower end with adownwardly and inwardly tapering external slip expander surface 31. Borewall 30a is provided with an internal annular recess 32 extending overits lower portion. The upper portion of bore wall 30:: has a diametersuch as to have close sliding engagement with the exterior of theportion of body 22 which extends below shoulder 24. A radial port 33 isprovided through the wall of body 22 below shoulder 24 and is adapted tocommunicate with a radial port 34 extending through the wall of slipcone 30 when shoulders 28 and 24 are in engagement, whereby to providefluid communication between the bore of body 22 and the exterior of thepacker assembly.

Mandrel M is provided intermediate its ends at about its mid-point withan external annular shoulder 35 adapted to be engaged by the lower endof body 22 to limit downward movement of the packer assembly relative tothe mandrel. A latch means is provided for releasably hold ing body 22in the shoulder-engaging position and includes a plurality ofcircumferentially arranged positioning lugs mounted for radial movementin slots 37 extending through the wall of body 22 just above the lowerend thereof. Lugs 36 have a radial length greater than the wallthickness of the lower portion of body 22 so as to be projectable fromslots 37 into an annular latching groove 38 provided in the exterior ofmandrel M just above shoulder 35 when the opposite ends of lugs 36 areengaged by bore wall 30a of the slip cone. It will be evident that whensuch relative longitudinal movement occurs between slip cone 30 andpacker body 22 as to move recess 32 opposite lugs 36, the latter will befreed for retractive movement out .of groove 38, thereby releasingmandrel M for longitudinal downward movement relative to packer assemblyS.

Anchor assembly A, which is positioned below packer assembly S, includesa tubular slip cage 40 on the upper end of which a plurality of upwardlyextending circumferentially arranged pipe-gripping slips 41 are mountedfor radial movement. The outer faces of the slips have the usualpipe-gripping teeth 41a and the inner faces of slips 41 are providedwith upwardly and outwardly bevelled surfaces 42 for cooperativeengagement with tapered surfaces 31 of slip expander cone 30. Cage 40 isprovided with an external annular recess 43 in which are mounted forlimited radial movement a plurality of friction pads 44, separated byspacer blocks 44a. Pads 44 are biased outwardly by means of coil springs45 to frictionally engage the wall of casing W.

The lower end of cage 40 supports still another latch mechanism whichcomprises a'tubular sleeve 46 surrounding mandrel M and having aninternal ledge 47 on which a plurality of latch segments 48 are rockablymounted for movement inwardly and outwardly of sleeve 46. A garterspring 48a is mountedto encircle the outer peripheries of the latchsegments to bias them toward mandrel M. The upper ends of latch segments48 define shoulders 49 adapted to engage beneath an external shoulder 50provided on mandrel M at a suitable spacing below shoulder 35. As in theposition illustrated in FIG. 1, it will be seen that latch segments 48will be engaged beneath shoulder 50 so as to prevent relative downwardmovement of mandrel M. Mandrel M carries a release mechanism forreleasing latching segments 48 from their engagement beneath shoulder50. This release mechanism comprises a trip sleeve 51 slidably mountedon the mandrel below shoulder 50 and is provided with an externalshoulder 52 at its lower end of greater diameter than the bore of ledge47. In the inactive position seen in FIG. 1, trip sleeve 51 will rest onshoulder 11 defined by lower collar C At its upper end trip sleeve 5-1has ;a shoulder 53, the external diameter of which is such as to permitit to slide freely through bore 46a of ledge 47, Shoulder 53 merges intoa downwardly and inwardly tapering surface 54 extending to the exteriorof sleeve 51. Trip sleeve 51 will be operated to release the engagementbetween the latch segments and shoulder 50 in response to thelongitudinal movement of the mandrel, as will be described hereinafter.This last-described latch mechanism, while differing in detail, is ofthe same general form and function as that described in my U.S. PatentNo. 2,884,069 and is intended to be generally illustrative of a form oflatch which is releasable by a series of reciprocative longitudinalmovements of the operating string and mandrel.

Operation of the described device is as follows: The packer structure,with the parts positioned as shown in FIG. 1, will be run into casing W.As shown, body 22 will be engaged with shoulder 35 on the mandrel andpositioning lugs 36 will be seated in latching groove 38. Also, byreason of the frictional engagement of pads 44 with the wall of easingW, which restrains movement of the anchor assembly, shoulder 50 on themandrel will engage the upper ends of latch segments 48, whereby the:

4 several sub-assemblies will be held in the spaced relation illustratedin FIG. 1.

When the structure has been moved to the desired location in casing W,operating string will be raised, raising mandrel M until trip sleeve 51seated on shoulder 11 has been drawn upwardly inside sleeve 46 movingshoulder 53 inside the latch segments and forcing them outwardly againstthe resistance of garter spring 48a until shoulder 53 has moved slightlyabove the upper ends of the latch segments 48. This upward movement willbe limited by the engagement of shoulder 52 With the lower end of sleeve46. This position of the parts is shown in FIG. 2. Thereupon, theoperating string carrying mandrel M is lowered and the latter will movedownwardly relative to trip sleeve 51 as the latter will be held in theraised position by the frictional engagement of latch segments 48 ontapered surface 54 under the pressure of garter spring 48a. When thestring has been lowered to the point where shoulder 50 abuts the upperend of shoulder 53 on the trip sleeve, the latter will be forceddownwardly past latch segments 48. Shoulder 50, which will haveapproximately the same external diameter as shoulder 53 will then movewith shoulder 53 below latch segments 48, thereby releasing the. mandrelfor further downward movement relative to the anchor assembly. As themandrel is lowered further, slip expander cone 31 will move inside slips41, as seen in FIG. 3, expanding the latter into gripping engagementwit-h the wall of casing W and stopping further downward movement of theassembly. However, as further weigh-t is applied to the operatingstring, packer body 22 carrying seal element 25 will move downwardlyrelative to slip cone 30, causing endwise compression of packer element25 and expanding it radially into sealing engagement with the wall ofeasing W. The resulting downward movement of body 22 relative to slipcone 30 will move positioning lugs 36 opposite recess 32, allowing thepositioning lugs to retract from latching groove 38 and releasing themandrel for downward movement relative to the packer assembly. Thecontinued downward movement of the mandrel will move latch and sealassembly L inside counterbore 23 and packing 12 will seal off theannular space between mandrel M and the packer body above hold-downbuttons 29. Dogs 19 will move into latching groove 24, being held inlatching engagement in the groove by upper end ring 13, which will be inengagement with shoulder 15.

When this series of operations have been completed, the packer will .beset, being anchored to the well wall by slips 41 and packed-off throughthe expansion of seal element 25. At the same time, packing 12 havingsealed off the annular space between the mandrel and the packer body,will permit pressure from below to flow through this annular space andactuate hold-down buttons 29 to cause them to engage the wall of casingW and hold the packer against upward movement under such pressure frombelow. Pressure from below the packer, which is acting upward againstthe mandrel M and packing 12, tending to push the mandrel M and packing12 out of the packing body 22, will act through the packing 12, end ring13, and tapered surface 20 to urge the latch dogs 19 outward intolatching groove 24, thereby pressure-locking the mandrel M intoengagement with packing body 22.

Torelease the packer, an upward pull is applied to operating string T tolift mandrel M straight upwardly. Through engagement of latch dogs 19with latching groove 24, body 22 will begin to move upwardly, relievingthe weight from seal element 25 which will then partially retract. Asbody 22 is further elevated it will move upwardly relative to slip cone30 until the outer ends of positioning lugs 36 engage the upper wall ofrecess 32 momentarily stopping the relative upward movement of body 22.A continued upward pull on mandrel M will then bring shoulder 15a intoengagement with shoulder 17a of the upper latch sleeve and will exert anupward pull on latch dogs 19. The reaction of the latter against theupper wall of latching groove 24 will force the latching fingersinwardly, pushing seal packing 12 downwardly sufficiently to allow thelatch dogs to clear groove 24 and permitting further upward movement ofmandrel M relative to the packer and pulling the latch and seal assemblyL out of counterbore 23. As mandrel M moves upwardly, shoulder 35 willmove up against the lower end of body 22, placing latching groove 38 inregistration with positioning lugs 36 and allowing them to project intogroove 38, thereby returning body 22 to its initial inactive position.Shoulder 2.4 will now engage beneath shoulder 28 on lower end ring 27 ofthe packer assembly and will exert an upward pull on slip cone 30 as themandrel continues to be pulled upwardly. This will pull slip cone 30from under slips 4-1, releasing the slips from the casing wall. As themandrel continues its upward movement, trip sleeve 51 will again enterthe bore of sleeve 46 and shoulder 52 will engage the lower end ofsleeve 46, so that the continued upward movement of the tubing stringwill pull anchor assembly A and all of the packer structure upwardly outof the casing.

If it is desired to reset the packer at a higher elevation, thestructure may now be moved to such elevation and be reset by a sequenceof vertical movements exactly as those previously described. If it isdesired to reset the packer at a lower elevation, then the tubing stringwould only be picked up enough to release the cone from the slips andbring shoulder 50 above the latch segments 48, but not enough to bringthe trip sleeve 51 up under the latch segments. Then the packer may belowered through the well and reset by a sequence of vertical movementsexactly as thoes previously described.

From the foregoing, it will be evident that a packer structure has beenprovided which meets the several objects enumerated and which is highlyuseful in well operations.

It will be understood that various alterations and changes may be madein the details of the illustrative embodimentwithin the scope of theappended claims,

but without departing from the Spirit of this invention.

What I claim and desire to secure by Letters Patent is:

1. In a well packer of the straight-set type, a tubular mandrelconnectible to an operating pipe string, a tubular packer body slidablymounted about the mandrel, an annular radially expansible seal elementmounted about the packer body having its upper end fixedly secured tothe body and its lower end free for relative longitudinal movement, aslip cone carried by said lower end of said seal element for saidmovement therewith, a slip cage slidably mounted on the mandrel belowthe packer body and carrying means for frictionally engaging asurrounding well wall, radially movable wall-gripping slips mounted onthe slip cage below said slip cone, cooperating latch elements arrangedon the mandrel and the slip cage for initially securing said mandrelagainst downward movement relative to said slip cage, means carried bythe mandrel operable by reciproca-tive longitudinal movement of themandrel relative to the slip cage to release said latch ele ments tothereby release said mandrel 'for said downward movement whereby to movesaid slip cone into expansive engagement with said slips, additionalcooperating latch elements arranged between the mandrel and the packerbody to initially secure the mandrel against downward movement relativeto the packer body and releasable by relative longitudinal movementbetween the packer body and said slip cone produced by engagement of thelatter with the slips whereby to free said mandrel for downward movementrelative to the packer body, and latch means of the straight-pullrelease type mounted on the mandrel above the packer body for latchingthe mandrel thereto upon completion of said downward movement of themandrel relative to the packer body.

2. In a well packer of the straight-set type, a tubular mandrelconnectible to an operating pipe string, a tubular packer body slidablymounted about the mandrel, an annular radially expansible seal elementmounted about the packer body having its upper end fixedly secured tothe body and its lower end free for relative longitudinal movement, aslip cone carried by said lower end of said seal element for saidmovement therewith, a slip cage slida'bly mounted on the mandrel belowthe packer body and carrying means for frictionally engaging asurrounding well wall, radially movable wall-gripping slips mounted onthe slip cage below said slip cone, cooperating latch elements arrangedon the mandrel and the slip cage for initially securing said mandrelagainst downward movement rela- .tive to said slip cage, means carriedby the mandrel operable by reciprocative longitudinal movement of themandrel relative to the slip cage to release said latch elements tothereby release said mandrel for said downward movement whereby to movesaid slip cone into expansive engagement with said slips, additionalcooperating latch elements arranged between the mandrel and the packerbody to initially secure the mandrel against downward movement relativeto the packer body and releasable by relative longitudinal movementbetween the packer body and said slip cone produced by engagement of thelatter with the slips whereby to free said mandrel for downward movementrelative to the packer body, latch means of the straight-pull releasetype mounted on the mandrel above the packer body for latching themandrel thereto upon completion of said downward movement of the mandrelrelative to the packer body, and seal packing positioned on the mandrelto seal between the latter and the packer body upon said completion ofsaid last-mentioned downward movement.

3. In a well packer of the straight-set type, a tubular mandrelconnectible to an operating pipe string, a tubular packer body slidablymounted about the mandrel, an annular radially expansible seal elementmounted about the packer body having its upper end :fixedly secured tothe body and its lower end free for relative longitudinal movement, aslip cone carried by said lower end of said seal element for saidmovement therewith, a slip cage slidably mounted on the mandrel belowthe packer body and carrying means for frictionally engaging asurrounding well wall, radially movable wall-gripping slips mounted onthe slip cage below said slip cone, cooperating latch elements arrangedon the mandrel and the slip cage for initially securing said mandrelagainst downward movement relative to said slip cage, means carried bythe mandrel operable by reciprocative longitudinal movement of themandrel relative to the slip cage to release said latch elements tothereby release said mandrel for said downward movement whereby to movesaid slip cone into expansive engagement with said slips, additionalcooperating latch elements arranged between the mandrel and the packer:body initially held in engagement by said slip cone to initially securethe mandrel against downward movement relative to the packer body andreleasable by relative longitudinal movement between the packer body andsaid slip cone produced by engagement of the latter with the slipswhereby to free said mandrel for downward movement relative to thepacker body, latch means of the straight-pull release type mounted onthe mandrel above the packer body for latching the mandrel thereto uponcompletion of said downward movement of the mandrel relative to thepacker body, and seal packing positioned on the mandrel to seal betweenthe latter and the packer body upon said completion of saidlast-mentioned downward movement.

4. In a well packer according to claim 3, wherein said additional latchmeans includes a latching groove in the exterior of the mandrel, and aplurality of lug members mounted on said packer body for radial movementinto and out of latching engagement with said latching groove.

5. In a well packer of the straight-set type, a tubular mandrelconnectible to an operating pipe string, a tubular packer body slidablymounted about the mandrel, an annular radially expansible sealelementmounted about the packer body having its upper end fixedly secured tothe body and its lower end free for relative longitudinal movement, aslip cone carried by said lower end of said seal element for saidmovement therewith, a slip cage slidably mounted on the mandrel belowthe packer body and carrying means for frictionally engaging asurrounding well wall, radially movable wall-gripping slips mounted onthe slip cage below said slip cone, cooperating latch elements arrangedon the mandrel and the slip cage for initially securing said mandrelagainst downward movement relative to said slip cage, means carried bythe mandrel op- I erable by reciprocative longitudinal movement of themandrel relative to the slip cage to release said latch elements tothereby release said mandrel 'for said downward movement whereby to movesaid slip cone into expansive engagement with said slips, externalshoulder means on the mandrel .abuttable by said packer body to limitdownward movement of the packer body relative to the mandrel, additionalcooperating latch elements arranged between the mandrel and the packerbody above said shoulder means initially held in engagement by said slipcone to initially secure the mandrel against downward movement relativeto the packer body and releasable by relative retractive movement ofsaid slip cone produced by engagement of the latter with the slipswhereby to free said mandrel for downward movement relative to thepacker body, top latch means of the straight-pull release type mountedon the mandrel above the packed body for latching the mandrel theretoupon completion of said downward movement of the mandrel relative to thepacker body, and seal packing positioned on the mandrel to seal betweenthe latter and the packer body upon said completion of saidlast-mentioned downward movement.

6. In a well packer according to claim 5, wherein said additional latchmeans includes a latching groove in the exterior of the mandrel above'said external shoulder means, and a plurality of lug members mounted onsaid packer body for radial movement into and out oflatchin-g engagementwith said latching groove.

7. In a well packer according to claim 5, a plurality of hold-down slipelements mounted in the packer body above said seal element for radialoutward movement in response to fluid pressure entering the annularspace between the mandrel and the packer body below said seal packing.

References Cited by the Examiner UNITED STATES PATENTS 3/1908 Robinson166 -138 10/1956 Brown 166--138

1. IN A WELL PACKER OF THE STRAIGHT-SET TYPE, A TUBULAR MANDRELCONNECTIBLE TO AN OPERATING PIPE STRING, A TUBULAR PACKER BODY SLIDABLYMOUNTED ABOUT THE MANDREL, AN ANNULAR RADIALLY EXPANSIBLE SEAL ELEMENTMOUNTED ABOUT THE PACKER BODY HAVING ITS UPPER END FIXEDLY SECURED TOTHE BODY AND ITS LOWER END FREE FOR A RELATIVE LONGITUDINAL MOVEMENT, ASLIP CONE CARRIED BY SAID LOWER END OF SAID SEAL ELEMENT FOR SAIDMOVEMENT THEREWITH, A SLIP CAGE SLIDABLY MOUNTED ON THE MANDREL BELOWTHE PACKER BODY AND CARRYING MEANS FOR FRICTIONALLY ENGAGING ASURROUNDING WELL WALL, RADIALLY MOVABLE WALL-GRIPPING SLIPS MOUNTED ONTHE SLIP CAGE BELOW SAID SLIP CONE, COOPERATING LATCH ELEMENTS ARRANGEDON THE MANDREL AND THE SLIP CAGE FOR INITIALLY SECURING SAID MANDRELAGAINST DOWNWARD MOVEMENT RELATIVE TO SAID SLIP CAGE, MEANS CARRIED BYTHE MANDREL OPERABLE BY RECIPROCATIVE LONGITUDINAL MOVEMENT OF THEMANDREL RELATIVE TO THE SLIP CAGE TO RELEASE SAID LATCH ELEMENTS TOTHEREBY RELEASE SAID MANDREL FOR SAID DOWNWARD MOVEMENT WHEREBY TO MOVESAID SLIP CONE INTO EXPANSIVE ENGAGEMENT WITH SAID SLIPS, ADDITIONALCOOPERATING LATCH ELEMENTS ARRANGED BETWEEN THE MANDREL AND THE PACKERBODY TO INITIALLY SECURE THE MANDREL AGAINST DOWNWARD MOVEMENT RELATIVETO THE PACKER BODY AND RELEASABLE BY RELATIVE LONGITUDINAL MOVEMENTBETWEEN THE PACKER BODY AND SAID SLIP CONE PRODUCED BY ENGAGEMENT OF THELATTER WITH THE SLIPS WHEREBY TO FREE SAID MANDREL FOR DOWNWARD MOVEMENTRELATIVE TO THE PACKER BODY, AND LATCH MEANS OF THE STRAIGHT-PULLRELEASE TYPE MOUNTED ON THE MANDREL ABOVE THE PACKER BODY FOR LATCHINGTHE MANDREL THERETO UPON COMPLETION OF SAID DOWNWARD MOVEMENT OF THEMANDREL RELATIVE TO THE PACKER BODY.